He became the most-expensive German footballer of all-time — a record he held for a couple of months before Mesut Ozil joined Arsenal for £42million — when he sealed a £32m move to Bayern Munich in 2013.

But he struggled to establish himself in Pep Guardiola‘s team and made his return to Dortmund last summer.

Things didn’t improve as fitness problems saw him in-and-out of the team before he was struck down by the virus.